Brief introduction:
Hydraulic ram BOP is an important part of wellhead, with the characteristic of quick switch, easy operation, use safety, easy maintenance, etc.

1, Use
To seal the annular space between casing and tubing string, and close wellhead. In the closed case, through the pipeline of under cross or side outlet of the shell to conduct drilling fluid circulation, choke blowout and kill the well ,etc. Under special conditions, can achieve the purpose of sealing well by cutting drilling tools and hanging drilling tools. Use reducing ram can close annular space of different specifications of the tubing string and casing in some range.

2, Structure characteristics:
(1) the structure characteristics of the shell prefer to above picture;
1) Shape. General shell is approximate square. There is ram chamber which has vertical hole and ram move horizontally for transmitting the drilling tools.
2) Connection type. There are three kinds of connection type for upper and bottom: bolt plant connection, flange connection, the clamp connection. The connecting flange, bolts, clamp, steel ring size are according to API standard.
(2) Ram structure and using characteristics: Ram structure show in following page.
Double side ram, ram upper and under faces are symmetrical. Different sizes of the drill tools only replace the rubber seal half ring and ram lock block, the rest parts are interchangeable. Use single face ram can not flip. Shear ram can cut off wellhead and full close it. Reducing ram is used in sealing different sizes of drill tools and casing in a certain range.
(3) Sealing characteristics of ram

Ram floating, automatic cleaning and well pressure to seal ram automatic centering and self entering. There are four sealing when ram preventer seal the wellhead to achieve effective seal. Namely: the sealing of ram upper and shell, the sealing of ram front end and pipe, the sealing of shell and side door, the sealing of piston rod and the side door.